Vapor-converter system



L. w. CHUBB.

VAPOR CONVERTER SYSTEM.

APPLICATION FILED DEC.2. I9l5.

lNVENTOR 3 wwas W Chum.

ATTORNEY Patented Dec. 2, 1919.

WITNESSES UNITED STATES PATENT OFFICE.

LEWIS W. GHUBB, 0F EDQEWOOD PARK, PENNSYLVANIA, ASSIGNOR T'O WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

VAPOR-CONVERTER SYSTEM.

To all whom it may concern:

Be it known that I, LEWIS W. CHUBB, a citizen of the United States, and a resident of Edgewood Park, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Vapor-Converter Systems, ofwhich the following is a specification.

My invention relates to high-tension unidirectional-current electric systems, such, for example, as are employed in smoke precipitation and in X-ray work, and it has for its object to provide means whereby a plurality of vapor converters or similar apparatus may be employed for the building up of the desired unidirectional potential without such concentration of the voltage stress in any part of the system as to necessitate large and expensive insulating means.

The single figure of the accompanying drawing is a diagrammatic; view of a system embodying a plurality of series-connected vapor converters, together with their attendant supply and 'keep-alive circuits,

arranged in accordance with my invention.

In Patent No. 1,186,747, issued to the Westinghouse Electric &- Manufactur ng Company on June 13, 1917, on an application filed by me, I have disclosed an arrangement of rectifiers of the electrolytic type whereby extremely high unidirectional potentials may be obtained, the apparatus being so'adjusted that there are no abrupt changes in the intensity of the electrostatic field and, hence, little liability to voltage break-down because of excessively steep potential gradients. In the present invention, I obtain similar results by the use of vapor converters of the usual type and avail myself of condenser action in the supply transformer in order to regulate the voltage distribution therein in somewhat the man'- ner set forth at length in IIS. Patent No. 1,129,463, issued to the Westinghouse Eleotric & Manufacturing Company, Feb. 23, 1915, on an application filed by Chas. LeCr. Fortescue. Briefly, said patent discloses a mass of insulating material disposed to insulate a winding in which a high'voltage is developed, layers of tin foil being disposed throughout said mass in normal relation to the electrostatic flow lines, and said layers of tin foil being progressively connected to points of progressively higher potential in said winding, whereby the condenser action Specification of Letters Patent.

Patented Dec. 2, 1919.,

Application filed December 2, 1915. Serial No. 64,636.

between said layers maintains a uniform potential gradient throughout said mass,

and failure thereof is prevented. A marked distinction should be noted, however, betweenthe structure disclosed in said patent and that of the present application in that said patentee places reliance uponthe layers of tin foil interposed throughout the insulating masses and respectively connected to different Sections of the high-voltage winding to efiect proper voltage distribution, whereas I so dispose the different secondary windings of a high-voltage transformer that they constitute condensers among themselves and produce the same result.

Referring to the accompanying drawing for a more detailed understanding of my invention, a plurality of vapor converters of the usual type are shown at 1,2, 3 and 4. Each of said converters is provided with a pair of main anodes 55, a main cathode 6 and a pair of auxiliary or keep-alive anodes 7. Alternating current is supplied to the converters 1' to 4, inclusive, from the secondary windings 8, 9, 10 and 11 of a transformer 12, the primary winding 13 of which is connected across suitable alternating-current mains 1414. The secondary windings 8, 9, 10 and 11 are concentrically disposed upon the core of the transformer 12 in the form ofcylindrical layers and, as the diameter of successive windings increases, the length of said windings is de creased, as shown, in order that the area of the cylindrical surface produced by each winding shall be substantially the same. As a result, each immediately adjacent pair of secondary windings constitutes a condenser, and the capacities of all of said condensers are substantially alike, allifor the purpose of voltage distribution, as will be hereinafter pointed out. The converters 1, 2, 3 and 4 are connected in series relation for the production of a high unidirectional voltage, said connection being produced by connecting the anodes 5 of the converter 1 to the terminals of the secondary winding 8, connecting the cathode 6 of the converter load '15, to the midpoint of the secondary winding 8. With the connections as described, there is'a gradual accretion or increase of potential with each converter unit and the entire potential of the load is impressed between the mid point of the secondary Winding 8 and the terminals of the secondary wmding 11. There is a corresponding accretion or increase of potential in passing throughout the secondary windings from 8 to 11, and said potentials are maintained at the proper value for connection to the respective converters by the condenser action between the different secon-- dary windings, it being well known that the voltage across a plurality of series-connected condensers is divided up into a corresponding number of steps or portions so that the potential drop is uniformly distributed throughout said series of condensers.

It is necessary to provide keep-alive or maintaining apparatus for single-phase converters of the type shown and, whileit is possible to perform this function by providing magnetic leakage in the main transformer, it is generally preferable to resort to other means. A customary method of maintaining a keep-alive are within a converter is to arrange a source of direct current, such, for example, as a storage battery, to produce a small direct-current are within the container between an auxiliary anode and a main cathode. A keep-alive anode of said character is well adapted for the maintenance of large low-voltage converting units, but if, as in the present case, it is desirable to use an extremely large number of smallcapacity units connected in series relation, it

is necessary to associate a separate directcurrent source with each of said units and to carefully insulate all of said sources from ground and from each other, with resultant great expense and troublesome maintenance.

Again applying the principles set forth in the aforementioned patent, I may provide an extremely simple inexpensive and effective maintaining system in the following manner. An auxiliary transformer 16 is connected to be. supplied from the mains lat-11 through a phase-displacing device 17. The transformer 16 is provided with a plurality of secondary windings 18, 19, 20 and 21 arranged, respectively, as are the secondary windings 8 to 11 of the transformer 12. The terminals of the secondary winding 18 are connected to the auxiliary anodes 7 in the converter 1, and the cathode of said converter is connected to the mid-point of said second- 'ary winding, whereby a small local rectify- -is ;i nitiated in anywell known manner, as by ing circuit is established. A keep-alive arc pressing high voltage upon an-auxiliary :de or by automatically breaking contact .,betw'een anauxiliary anode and the cathode;

current impulses in said keep-alive circuit are displaced from those in the main power circuit by the device 17, whereby the converter 1 is maintained in an active condition, as is well known in the art. In like manner, the secondary winding 19 is associated with the converter 2, the secondary winding 20 with the converter 3 and the secthe main power circuit, the terminals of a secondary winding are connected to the anodes of the converter, and the cathode of said converter is connected to the mid-point of a neighboring secondary winding, thus establishing the series connection, whereas, in the maintainin circuits, the terminals of a secondary win ing are connected to the auxiliary anodes of a converter, and the cathode of said converter is connected back to the mid-point of the same secondary winding, whereby the maintainin circuits are maintained entirely distinct rom each other except for the condenser action therebetween.

If it be desired to derive high-potential direct current from a polyphase supply circuit, the transformer 12 may be duplicated and energy supplied to an additional main anode or anodes in the converters. The system thus evolved is self-maintaining, as is well known in the art, and, hence, the auxiliary transformer 16 may be dispensed with.

\Vhile I have shown my invention in its preferred form, it will be obvious to those skilled in the art that it is susceptible of various minor changes and modifications without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be laced thereupon as are imposed by the pIlOI art or are indicated in the appended claims.

I claim as my invention:

1. The combination with a transformer provided with a plurality of secondary windings, of a plurality of series-connected rectifying units, each of said units being connected to derive energyfrom one of said secondary windings, and means for providing capacity between said secondary windings, whereby each tends to assume the potential of its associated rectifying unit.

2. The combination with a transformer provided with a plurality of secondary windings arranged in the form of concentric layers, of a plurality of series-connected rectifying units, connections from the innermost secondary winding to one of the terminal rectifying units, and connections from successive remaining units to successive outer layers, whereby the inherent capacity between said layers tends to maintain the potential of each layer at the potential of its associated rectifying unit, v

3: The combination with a transformer provided with a plurality of secondary windings arranged in the form of concentric layers of substantially equal superficial area, of a plurality of series-connected rectifying units, connections from the innermost secondary winding to one of the erminal rec-tifying units, andconnections' f om successive remaining units to successive outer layers, whereby the inherent capacity between said layers tends to maintain the potential of each layer at the potential of its associated rectifying unit.

4. The combination with a transformer provided with a series of secondary wind ings having substantially equal capacity between pairs of immediately adjacent windings, of a plurality of series-connected vapor l are converters, connections from one of the end windings of said series to the main anodes of one of the terminating converters,

' connections from each succeeding secondary winding to the main anodes of an immediately succeeding converter, and a connection from the cathode terminal of each converter to the mid-point of the supply winding 0 the immediatelytsucceeding converter. 1

5. The combination with' a transformer provided with a series of secondary windings having substantially equal capacity between pairs of immediately adjacent windings, of a plurality of series-connected vas por-arc converters, connections from one of the end windings of said series to the main anodes of one of the terminating converters, connections from each succeeding secondary winding to the main anodes of an immediately succeeding converter, a connection from the cathode terminal ofeach converter to the midpoint of the supply winding of the immediately. succeeding converter, an auxiliary similarly constructed transformer displaced in phase from said" first transformer, successive connections. from each secondary winding thereof to the maintaining anodes of one of said units, whereby,the auxiliary, secondary windings tend to .be' maintained at. the potential of their associated converters, and connections from the cathode of each converter to the mid-point of its associated auxiliary supply winding.

6. The combination with an electric circuit including a plurality of series-connected devices, of means for maintaining a potential across each thereofand .comprising a transformer provided with a plurality-of secondary windings so arranged that immediately adjacent pairs of windings con stitute condensers, connections from the terminals and mid-point of one of said windings to one of said devices, and connections from the terminals and mid-point of each succeeding winding to an immediately succeeding device;

7. The combination with an electric circuit, of means for establishing a unidirecfrom the terminals of each succeeding winding to the auxiliary anodes ofeach succeeding converter and from the mid-point of each of said windings'to the cathode of the associated-converter. I

8. The combination with an electric circuit, of means for establishing a' unidirectionalE. M. F. therein comprising a plurality of series-connected vapor arc converters,

keep-aliveapparatus for each of said converters comprising 'apair of auxiliary anodes and a cathode therein, a transformer provided with a plurality of concentrically arranged secondary windings of substan- Y Y tially equal areas, connections from the terminals of the inner winding to the auxiliary anodes of the first of said converters and from the-mid-point of said winding to the cathode of said converter, and connections from the terminals of each immediately surrounding winding' to the auxiliary anodes of an immediately succeeding converter andfrom the mid-point of each winding to the, a

' cathode of its associated converter.

In'testimony whereof, I have hereunto subscribed my name this 29th'day of Nov.

LEWIS w.cHUBB. 

